When scoundrels rig the thimble

Thimblerig is a "gambling" game better known as the three shell game or three shells and a pea. When it’s played with cards it’s called Three Card Monte. A player bets to locate the pea or the right card. It’s a con game where the operator can shift the desired object away from the suspected location. The player always loses his money.

The novelist William Makepeace Thackeray wrote about his encounter with a thimble rigger during a visit to the horse races at Killarney, Ireland in 1845:

A ragged scoundrel – the image of Hogarth’s Bad Apprentice – went bustling and shouting through the crowd with his dirty tray and thimble, and as soon as he had taken his post, stated that this was the "royal game of thimble" and called upon "gintlemen" to come forward. And then a ragged fellow would be seen to approach, with as innocent an air as he could assume, and the bystanders might remark that the second ragged fellow almost always won. Nay, he was so benevolent, in many instances, as to point out to various people who had a mind to bet, under which thimble the pea actually was. Meanwhile, the first fellow was sure to be looking away and talking to some one in the crowd; but somehow it generally happened – and how of course I can’t tell – that any man who listened to the advice of rascal No. 2, lost his money. I believe it is so even in England.

The victim usually never realizes they’re all in on it.
Half a century later, the con was still being played. In this account from 1894, the victim becomes the victor:

In the early days the three-card trick was not the national institution it has since become; the "gentlemen of the road" at that time used the three thimbles. The Cambridge Line was much infested by these persons till cleared of them by a well-known personage, whom I will call Mr. Hunt. He was a London money-lender of great disrepute, whom some of my young friends had dealings with, and perhaps he resented that the sovereigns which ought by right to have been his found their way into these rascals pockets. At all events he undertook the (to him) unusual role of the guardian of youth and public benefactor.

Mr. Hunt was a tall and powerful man but had the agile fingers of a conjurer, and thimble-rig was child’s play to him. Attired richly with studs and chain, and with an agricultural cast of countenance, his entrance into their compartment was gladly welcomed by the three rogues. After a modest interval, the thimbles were produced, and he lost a pound or two; then, pretending to be "pricked," as the gamblers call it, he offered to bet &#163;25 that he would discover the pea. The money was staked on both sides and put on a. vacant seat. Then Mr. Hunt said, after an apparently careful inspection, "The pea is there." and there it was under the thimble. Then he seized the banknotes, crammed them into his pocket, and produced a life preserver. (Editor’s note: a "life preserver" was a weapon such as a bludgeon, club or blackjack.) "Whoever touches me," he remarked, "is as good as dead."

The three sharpers had the sense to perceive that he was in earnest, and they were also astonished and demoralized by what they had witnessed; for nobody; knew better than themselves that there had been no pea. Mr. Hunt also knew it and had brought one with him to supply the deficiency. They never trouble the Cambridge Line again.

– The Thimble-Rig Trick, an account by James Payn in The Cornhill Magazine, from the September 16, 1894 edition of The New York Times.– The Irish Sketch-book by William Makepeace Thackeray [1845], Sacred Texts>>